1. Field of the Invention
The present invention relates to a cartridge provided with a rotating member, and attachable to and detachable from an electrophotographic image forming apparatus (hereinafter, referred to as an image forming apparatus).
A development cartridge includes at least a developer bearing member (hereinafter, simply referred to as “developing roller”), and is attachable to and detachable from the image forming apparatus main body.
A process cartridge is formed by integrating an image bearing member and, at least a charging unit and a developing unit into a single cartridge, and is attachable to and detachable from the image forming apparatus main body
2. Description of the Related Art
There are some image forming apparatuses such as a copying machine, a printer, and a facsimile, in which a development cartridge or a process cartridge is attachable thereto and detachable therefrom. A developing unit included in the development cartridge or the process cartridge develops an electrostatic latent image formed on a surface of an image bearing member and visualizes the image as a toner image. At this point, the development cartridge is configured by integrating a developing roller for developing an electrostatic latent image formed on the image bearing member, a toner storing unit for storing developer (hereinafter, simply referred to as “toner”), and a developing blade for regulating thickness of a toner layer on the developing roller into a single cartridge. Then, the development cartridge is configured to be attachable to and detachable from the image forming apparatus main body. On the other hand, the process cartridge is configured by integrating an image bearing member such as a photosensitive drum, a developing roller for developing an electrostatic latent image formed on the image bearing member, and a toner storing unit for storing toner into a single cartridge. Then, the process cartridge is configured to be attachable to and detachable from the image forming apparatus main body
Each of the development cartridge and the process cartridge is provided with a developing roller, and a developing roller supporting member for rotatably supporting the developing roller from both end portions of the developing roller. In particular, in order to rotate such the developing roller smoothly on the developing roller supporting member, the invention relating to a grease groove formed on a shaft portion, which is discussed in Japanese Patent Application Laid-Open No. 07-304233 (especially in FIG. 7) can be applied. The invention discussed in Japanese Patent Application Laid-Open No. 07-304233 itself (especially in FIG. 7) is relates to a configuration in which a grease groove is formed on a shaft portion formed on a drive cover, grease is applied to the grease groove, and a gear is attached to the shaft portion. With such configuration, sliding resistance in the shaft portion and the gear is reduced.
It is assumed that the developing roller is rotatably mounted on the developing roller supporting member. Then, it is assumed that the developing roller supporting member includes bearing portions in both end portions in a longitudinal direction, which receives both end portions of a shaft of the developing roller, and regulates a position of the developing roller in a shaft direction. If the invention of Japanese Patent Application Laid-Open No. 07-304233 described above may be applied to this configuration, for example, grease is applied to the grease grooves formed on the bearing portions, and a shaft portion of the developing roller is mounted on the bearing portions. With such configuration, sliding resistance between surfaces of the developing roller and inner side surfaces of the bearing portions is reduced (see FIGS. 10A to 10C of the present application).
However, in the configuration in which the above described developing roller (hereinafter, may be sometimes referred to as “rotating member”) is mounted on the developing roller supporting members, there is a risk, in the mounting process, that grease in the grooves and its surrounding may move to end surfaces of the shaft portions of the developing roller, thus making them dirty.
In particular, if a through-hole is formed on the bearing portion, and the end surface of the shaft portion of the developing roller is exposed, a possibility that a user may touch the end surface of the shaft portion of the developing roller seems to be high (see FIGS. 10A to 10C). In such case, when grease adheres to the end surface of the shaft portion of the developing roller, there is a risk that the user may touch the grease, which adheres to the user's hand. In order not to make the user's hand dirty with the grease, first of all, it is conceivable that the bearing portion is constituted of a bag-shaped hole so that the grease may not squeeze out to the outside. However, with this configuration, it is impossible to expose the end portion of the shaft portion of the developing roller and to bring it into contact with an electric terminal of a power supply unit. In order not to make the user's hand dirty with the grease, secondly, it is also conceivable to perform strict coating management of the grease so that the grease may not squeeze out. However, this configuration results in increase of product costs.